It's fine although you don't need R5 (and R1). Depending on what the input capacitance of the DVR134 is, then it might be good practice to add a 68 ohm or thereabouts in series with the output. And do you need a cap on the input ? That's source dependent of course but again, good practice.

It's fine although you don't need R5 (and R1). Depending on what the input capacitance of the DVR134 is, then it might be good practice to add a 68 ohm or thereabouts in series with the output. And do you need a cap on the input ? That's source dependent of course but again, good practice.

Thanks.

R1 was just put there for a load for the sim. Adding a series 68Ω resistor is a good idea. I'll add that one.

R5 can be deleted if it is not needed.

Yes, the source is fully decoupled with its own cap, so I did not want to add another cap in the signal path.

Did you check for input bias on that opamp? Input bias current through the DC input R can cause appreciable output offset. Especially when you use input capacitor: the +input bias current will flow through 470k and the -input bias current through zero.
BTW, why the need for 470k Zin? That's unusual in audio.

jan

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Did you check for input bias on that opamp? Input bias current through the DC input R can cause appreciable output offset. Especially when you use input capacitor: the +input bias current will flow through 470k and the -input bias current through zero.
BTW, why the need for 470k Zin? That's unusual in audio.

jan

The op amp is actually a OPA2134 with a FET input. Is bias still a concern?

The input impedance is driven by an old PAS 3 tube preamp and the output impedance for that preamp is required to be 470KΩ or nasty things happen to the frequency response (ask me how I know).

This circuit is just a quick & dirty fix until I complete my own DIY preamp.

If your feeding this from a tube amp then you must be certain that not only is the tube amps output cap OK but also that it has a high value resistor to ground (even if its 10meg) on the output. If not and its floating then the cap could charge to some high voltage and this would zap the IC as soon as you connected.